Unable to hear callers through iPhone unless its on speaker

If you can't hear callers unless the speaker is on or headphones are connected, the issue likely lies with the phone's ear speaker or audio settings. Troubleshooting involves checking volume settings, Bluetooth connections, and potential ear speaker blockage or damage. 

1. Check Volume Settings:

• Ensure the call volume is turned up on the phone and that the ringer volume is also set to a reasonable level.
• Sometimes, volume settings can be accidentally muted or set too low, even if the speaker appears to be functioning correctly. 

2. Investigate Bluetooth Connections:

• If you have a Bluetooth device connected (e.g., headphones, car system), disconnect it to see if the audio then works through the phone's ear speaker.
• Audio can sometimes be routed to the Bluetooth device instead of the phone's speaker. 

3. Clean the Ear Speaker:

• Dust or debris can block the ear speaker, preventing sound from being heard clearly. Gently clean the speaker opening with a soft brush or compressed air.

4. Check Audio Balance (if applicable):

• Some phones have an audio balance setting that controls how much audio is directed to each speaker. Ensure this is set to the middle, not biased towards one side,. 

5. Consider Hardware Issues:

• If none of the above steps work, the ear speaker might be damaged or faulty, requiring professional repair.

6. Check for Obstructions:

• Make sure nothing is blocking the speaker or microphone openings, such as a screen protector or a loose case. 

7. Restart or Update:

• A simple restart or updating the phone's software can sometimes resolve minor software glitches that affect audio,